Why do you have to enter a Passcode after restart?

[Armen]

All,

I know it sounds like an annoyance to have to enter your passcode after a restart instead of using TouchID but this is a blessing in disguise.

If the police or other authorities pull you over they can ask you to unlock your iPhone using TouchID but they cannot ask for your passcode or make you enter your passcode.

So next time you get pulled over and wish to protect your privacy merely restart your iPhone because you cannot unlock it after a restart with Touch ID.

 

[Julien]

This has nothing to do with with it. First your scenario is an extremely rare occurrence at best. Also you can't be forced to unlock your iPhone by the police. This requires a court order and that takes days. You can't use your Touch ID after 48 hours without reentering your passcode.

 

[Armen]

This has nothing to do with with it. First your scenario is an extremely rare occurrence at best. Also you can't be forced to unlock your iPhone by the police. This requires a court order and that takes days. You can't use your Touch ID after 48 hours without reentering your passcode.

For reference.

http://www.technobuffalo.com/2014/11/03/police-can-force-you-to-unlock-phone-with-touch-id-court-rules/

https://www.yahoo.com/tech/court-rules-police-may-force-you-to-unlock-your-phone-101683639779.html

http://www.huffingtonpost.com/2014/10/31/apple-touch-id-ruling_n_6083920.html

Warrant or not if you reboot your iPhone you have to enter a passcode as it won't accept TouchID

"The Fifth Amendment protects you from offering knowledge that could incriminate yourself, meaning you don't have to tell a cop your phone's password if he or she asks you for it. But you can be required to turn over physical evidence or DNA information. In the Virginia case, the judge ruled that a fingerprint is considered a physical object -- and police are allowed to force you to give it to them."

 

[dhlizard]

Or you could live your life on the up & up and the worst you might get pulled over for is a traffic ticket - which means your phone is a non-issue.

Problem solved.

 

[Julien]

For reference....

OK

"...This is one court ruling [in Virginia] for one lawsuit, so it’s not an overarching law that’s been put in place by the U.S. Supreme Court..."

 

[Stuntman06]

Or you could live your life on the up & up and the worst you might get pulled over for is a traffic ticket - which means your phone is a non-issue.

Problem solved.

Some people who live life on the up & up don't have much trust that law enforcement will follow the rules.

 

[Armen]

OK

"...This is one court ruling [in Virginia] for one lawsuit, so it’s not an overarching law that’s been put in place by the U.S. Supreme Court..."

Doesn't it always start that way?

 

[GoSh4rks]

OK

"...This is one court ruling [in Virginia] for one lawsuit, so it’s not an overarching law that’s been put in place by the U.S. Supreme Court..."

There's no law saying that they can't force you to unlock using your fingerprint though. That's the point.

 

[Woochifer]

To the question in the title, Apple requires entering a passcode to unlock the phone simply because the iPhone keeps the Touch ID decryption keys in memory rather than in storage. Any reset flushes out the memory, and the keys also get purged after 48 hours of non-use or 5 incorrect Touch ID entry attempts. Among other things, it prevents someone from accessing your data by moving the motherboard to another device. Here's the description from Apple's security white paper on the 5s:

How Touch ID unlocks iPhone 5s
On devices with an A7 processor, the Secure Enclave holds the cryptographic class keys for Data Protection. When a device locks, the keys for Data Protection class Complete are discarded, and files and keychain items in that class are inaccessible until the user unlocks the device by entering their passcode.

On iPhone 5s with Touch ID turned on, the keys are not discarded when the device locks; instead, they’re wrapped with a key that is given to the Touch ID subsystem. When a user attempts to unlock the device, if Touch ID recognizes the user’s fingerprint, it provides the key for unwrapping the Data Protection keys and the device is unlocked. This process provides additional protection by requiring the Data Protection and Touch ID subsystems to cooperate in order to unlock the device.

The decrypted class keys are only held in memory, so they’re lost if the device is rebooted. Additionally, as previously described, the Secure Enclave will discard the keys after 48 hours or 5 failed Touch ID recognition attempts.

As to the court case, this is just the first step. The judge seems to have gone by arcane semantics in differentiating between fingerprint scans and passcodes to unlock secured devices. Both are simply methods of accessing secure data by law enforcement. If the courts somehow maintain this differentiation, I would expect legislators to step in and pass laws that either declare mobile devices off-limits or compel user to unlock them regardless of whether a fingerprint or passcode is use.

 

[Julien]

To the question in the title, Apple requires entering a passcode to unlock the phone simply because the iPhone keeps the Touch ID decryption keys in memory rather than in storage. Any reset flushes out the memory, and the keys also get purged after 48 hours of non-use or 5 incorrect Touch ID entry attempts. Among other things, it prevents someone from accessing your data by moving the motherboard to another device. Here's the description from Apple's security white paper on the 5s:



As to the court case, this is just the first step. The judge seems to have gone by arcane semantics in differentiating between fingerprint scans and passcodes to unlock secured devices. Both are simply methods of accessing secure data by law enforcement. If the courts somehow maintain this differentiation, I would expect legislators to step in and pass laws that either declare mobile devices off-limits or compel user to unlock them regardless of whether a fingerprint or passcode is use.

This was my intent at an answer but better articulated and much more informative.

EDIT: I will add that the ruling on a finger print is based on things like Hair, blood, breath, saliva, and DNA samples. While a passcode is considered intellectual. While we see them as the same the law can see them as fundamentally different.

 

[Armen]

To the question in the title, Apple requires entering a passcode to unlock the phone simply because the iPhone keeps the Touch ID decryption keys in memory rather than in storage. Any reset flushes out the memory, and the keys also get purged after 48 hours of non-use or 5 incorrect Touch ID entry attempts. Among other things, it prevents someone from accessing your data by moving the motherboard to another device.

Your technical explaination just blew my mind.